Child's age helps determine if refractive error warrants correction

Issue: February 1997

PHILADELPHIA — The only constant with regard to refractive errors in infants and young children is the probability for change, according to Pennsylvania College of Optometry Professor Elise B. Ciner, OD. "Refractive errors change dramatically during the first 5 years of life, so the management of refractive error for these younger children is quite different from that of their older brothers and sisters," Ciner told Primary Care Optometry News, in an interview following her talk on refractive errors in children at the annual meeting of the American Optometric Association.

It is only in the past 10 to 15 years that eye exams are being recommended for children younger than 5. While age 6 was the norm for the recommended initial eye exam a decade ago, and age 3 was the norm more recently, today all of the major organizations, including the American Optometric Association (AOA), Prevent Blindness America and the American Academy of Ophthalmology, agree that a child's vision should be checked by 6 months of age. The AOA recommends a second examination at approximately 2 to 3 years old. Children should then be checked again at 5 years of age, says Dr. Ciner.

Wide range of errors

Infants are born with a wide range of refractive errors. During the first few years of life a "normalization process" — emmetropization — takes place, and often the error will disappear or diminish, according to Dr. Ciner. "Many infants have a refractive error at birth, but many of these errors disappear during the first 2 to 3 years of life. If we see a moderate amount of myopia in a 3-year-old we would certainly prescribe corrective lenses, but if we saw it in a 6-month-old we might not," she said.

Children can have significant degrees of myopia or hyperopia at birth, but because of emmetropization, Dr. Ciner explains, correction would generally be prescribed for these conditions only if there is at least a 5-D error by 6 months of age. "As the child gets older, we would prescribe for lesser and lesser amounts," she said, "because as the child grows, the likelihood of the error decreasing or improving is reduced."

Astigmatism is common in infants. "We usually don't prescribe for astigmatism in very young children, because in most cases it goes away by the time the child is 2 or 3 years old," Dr. Ciner said. "If it hasn't gone away by age 2 or 3, then we want to think about prescribing, if there is more than 1.25 D of error."

Anisometropia also has a higher prevalence in infants, but tends to go away. "In other instances it shows up later when it was not there in the first place," said Dr. Ciner. "In all cases, young children need to be checked at certain points during the first 5 years of life for other vision problems, in addition to refractive error."

Criteria for treatment

The degree of refractive error is not the only criteria for treatment, Dr. Ciner pointed out. "There are other factors that impact refractive error management, not just how much there is," she said. "If you have a child who is nearsighted at age 1, it is not really significant because most of what the child needs to see is close up; low amounts of nearsightedness are inconsequential. But if you take the same child with the same refractive error at age 4 who is now enrolled in a preschool program, he or she will need to see things far away, so it becomes more important to prescribe for lesser amounts of error as the child grows."

Another important consideration is the impact of refractive error on other aspects of visual development. "For example," Dr. Ciner explained, "you have to look at how it impacts on binocularity. Sometimes prescribing for refractive error can help align the eyes; in other cases it could actually worsen the binocularity. While you might not normally prescribe for a moderate amount of farsightedness, if that child also has one eye turning inward you could actually align the eyes by prescribing for the hyperopia."

Acceptance of the concept that infants as young as 6 months old should be refracted is far from widespread. "It is beginning to be recognized, but it is not well accepted," said Dr. Ciner. "We know how to examine young children, but it is only just now filtering down from the research labs, and it has not yet become part of standard clinical practice.

"If only pediatricians check the children's eyes, that is a problem because they never check for refractive errors," Dr. Ciner said. "Typically young infants are checked for normal tracking skills, media opacities (to make sure there are no cataracts or retinoblastoma) and a gross estimate of eye alignment."

For Your Information:
Contact Elise B. Ciner, OD, FAAO, at The Eye Institute of the Pennsylvania College of Optometry, 1200 West Godfrey Ave., Philadelphia, PA 19141-3399; (215) 276-6050; fax: (215) 276-6081.